Grab



May 3, 1932. w. VOORWINDE 1,856,232

GRAB

Filed March 4, 1.951

Patented May 3, 1932 UNITED STATES PATENT OFFICE WILLEM VOORWIINDE, FROT'I'ERDAM, NETHERLANDS GRAB Application filed March 4, 1931, SerialNo. 520,014, and in the Netherlands March 12, 1930.

The invention relates to an automatic grab other jaw. 6 to a fixed point11 of the firstfor controlling, i. e. regulating the closing mentionedjaw 5. force of automatic grabs with two jaws Thesecond closing rope 12,Fig. 3, within hinged together, said jaws being closed by the grab, hasnot been illustrated for clearmeans of one or more cables. ness sake.This cable or rope runs in a simi- 55 It is known that for working roughmalar manner over the pulleys of both jaws tel'ial, for instance ore,the closing of the and is fixed to a fixed point of the jaw 6. automaticgrab requires a force greater than Of course, each cable, instead ofrunning over the force wanted for working for instance only two pulleys,can run over a plurality 1o sand or corn. For this reason, in the firstof pulleys. 60 case cables with more blocks or more rollers For thepurpose of putting a portion of the will be used than in the secondcase. 11' one rope or cable between the pulley 10 and the and the samegrab is used for both purposes, fixed point 11 out of action, asaddle-shaped then always the difiiculty has to be overcome support 13is rigidly fixed under the head 15 that the grab takes either not enoughin the shaft 4E, at a short distance therefrom. 65 case of roughmaterial, or too much when As can be seen from Fig. 2, it is necessaryworking line grainy material. The insertion to lift the above-mentionedportion very of further rollers or putting them out of little if thegrab is in open position, for the service for the purpose of modifyingthe purpose of laying said portion of the rope co closing force takes upmuch time, especially upon the support 13. 70 because the cables to beinserted or to be The normal position of the cable is indieliminated arevery thick and still. cated by a dot and dash line, whilst the por- Theinvention aims to render possible the tion out of action is indicated bya dotted execution of this changing in a shorter time line. d o i t inprinciple in laying one 0 As can be seen from Fig. 3,the pulleys9andmore portions of the cable in the form of a 10 and also the fixed point11 are arranged loop over an appropriate support or ful- 1n Verticalplanes spaced apart from one an crum of the grab, thus putting thisportion ther, So that the rope or cable portlons run or portions whollyor partially out of action. wlthout touching one another. As the lengthof a thus guided part stays The Saddle-Shaped PP W111 be P so unvariableduring the closing of the grab or ably mounted and executed in such amanner varies less than under normal circumstances, that the length ofthe portion of the rope that portion will play no part or onl a laymg011 said support, thus between the fixed smaller part for determiningthe closing p in 11 an the 1 m W r h t p rt n force. leaves the pulley10, will be equal to the 35 The annexed drawings showdiagrammatidistance between the point 11 and the axis cally an automaticgrab, by way of example. of the top shaftfl, increased with the lengthFig. l is a side View of a closed grab; and of the tangent trom thataxls to the pulley Fig. 2 is a side View of an open grab ac- 10. Thislength will stay unvaried during 90 cording to the invention, whilst theclosing of the grab, so that the portion Fig. 3 is a front View,partially in vertical will then be Wholly put out of action. section. Ifthis prescription is not satisfied, the por- The automatic grab consistsof two jaws 5 tion of the rope or cable will only be partialand 6, fixedtogether by a hinge-like joint. ly put out of action. 95

The closing rope 7 runs in a known manner Now it is possible to stillmore exactly dethrough a hole in the head or top shaft 4, termine theclosing force, if the posltlon of then over a guiding roller 8 near tosaid top the guide-roller 8 may be changed in vertical shaft, furtherover a pulley 9 of one of the direction, or if one or more fixedsupports jaws 5 and then round a pulley 10 of the for the portlons ofthe rope or cable are we mounted to one or both aws of the grab, betweenthe head shaft and the tackle.

In this case, however, it is recommended to execute the support in theshape of a rotatable pulley 13, for avoiding the rubbing of the cableover its support.

Of course, a separate adjustable support may be provided for eachportion of the cable, and said support may be rotatably mounted.

I claim:

1. In an automatic grab, the combination of two jaws, a hinge-like jointconnecting together saidjawsyat .least .one cable carrying said grab, atleast one pulley on each jaw, one portion of the cable running over saidpulleys and fixed to a fixed point of-one jaw, and a support on the grabfor supporting that portion of the cable between the last pulley andsaid fixed point, for the purpose set forth.

2. In an automatic grab, the combination of two jaws, ahinge-like jointconnecting said jaws-together, at least one: cable for operating saidgrab and its jaws, at least one pulley on one jaw, a fixed point forattaching the end of the cable at the other jaw, at least one supportfor one portion of the cable, said support being mounted in such amanner that the length of the portion of the cable laying on saidsupport-is equal to the distance between said fixed point and thehinge-like joint increased with the length of the tangent from thathinge-like joint to said pulley.

In testimony whereof I signed hereunto my name.

WILLEM VO ORWINDE.

